http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57974
--- Comment #18 from Paolo Carlini <paolo.carlini at oracle dot com> --- Couple of clarifications: this doesn't go through cpow at all, the second argument isn't complex; this isn't -ffast-math, and in general in my experience whatever you throw at clang and icc (in fact, clang++ accepts the very same -f gcc accepts) like -Ofast, it never happens that exp(-inf) becomes nan (now I don't have the time to actually run benchmarks but since we are talking about compile-time constants I don't think we are beating them performance-wise on this); why long double is so special for exp(-inf), I don't think we can make a case for that, in terms of consistency or x87 crazyness (we are comparing also to icc not to a random compiler from people not really knowing the architecture). But sorry I'm not going to contribute much more to this discussion, at the moment I don't think I'm able to make the compiler concretely better and it only would make me nervous.
